Portable meteorological information system

ABSTRACT

A meteorological information system useable by aircraft pilots and others. A receiver-calculator unit receives raw meteorological data and site-specific physical data from a ground-based weather station having a signal transmitter for broadcasting signals conveying data about weather conditions at the station. The transmitted raw data signals are received by the receiver-calculator unit in the aircraft. The receiver-calculator unit may feature an input with which the operator inputs information about the physical character, such as the heading, of the runway of interest. The receiver-calculator unit processes both received raw weather data and received site-specific physical data, and/or operator-input data, to derive additional meteorological information. The raw and derived weather conditions information is displayed by the unit to be available to the aircraft pilot during landing or take-off maneuvers. Optionally, the apparatus uses known algorithms for determining aircraft performance characteristics to process raw and derived weather and site-specific data to determine the relative safety of proposed aircraft maneuvers, such as take-off.

BACKGROUND OF THE INVENTION

1. Field of the Invention (Technical Field)

The present invention relates generally to systems for providingmeteorological information, particularly to apparatuses for supplyingweather data to aircraft pilots, and specifically to a receiver andcalculator apparatus for simultaneously receiving, processing, anddisplaying weather and other data to pilots of private aircraft.

2. Background Art

Historically, pilots of private aircraft have relied on a wind sockviewed from 1,000 to 1,500 feet while flying over a private airfield orheliport to determine wind speed and direction. More recently, inairports having tower operations or a fixed base operator, aircraftpilots have used radio voice communication with operators at the airportto obtain important weather information, including wind speed anddirection. Within the last fifteen years at public airports in theUnited States, the federal government has installed automated weatherobservation systems (AWOS). AWOS measure airport weather conditions, andthen broadcast periodically updated voice recordings to transmit theinformation to aircraft near the airport. This system was recentlyupgraded to a more sophisticated Automated Surface Observing System(ASOS) at the 1,000 largest public U.S. airports. The ASOS systemprovides a variety of weather information via voice radio communicationto aircraft in the vicinity of the airport. Such automated systems cancost anywhere from $30,000 to $150,000 per airport. Both AWOS and ASOSrequire aircraft pilots to process audible (voice message) informationfrom a radio receiver in the aircraft. There are about 5500 publicairports in the United States that should 1 have automatic weathersystems provided by the federal and local government to facilitate airsafety for public air transportation. However, there are an additional13,200 private airstrips, heliports, and seaplane bases that, due tocost constraints, will not be instrumented via these federal programs.There is a need, therefore, for a low cost, reliable, alternativesystem.

Meteorological information is important, of course, to pilots of smallaircraft. Such weather factors as crosswind and headwind speed anddirection, wind gust speed and direction, and dew point temperatureinform the pilot's judgment, particularly during takeoff and landing.The pilot operating out of a small private airport may, at best, obtainsome basic absolute wind speed and direction, barometric pressure, andtemperature information from automated audio broadcasts from thefacility, or from live audio radio communication from the fixed-basefacility operator. At numerous remote airstrips, the pilot must stillrely upon a wind sock, or upon regional weather reports. Still, evenvoice communications from a fixed base operator or automated broadcastleave the pilot with the task of referring to printed graphs, charts,and nomographs, and operating hand-held standard electronic calculators,or maybe even performing handwritten calculations, to determine from rawaudio data such other vital information as cross wind and headwindspeeds and directions, dew point temperature, and the like. Stillfurther, the pilot should use the meteorological information thusdetermined to evaluate whether a takeoff or landing can be safelyperformed in his particular type of aircraft, under the given weatherconditions, on a particular runway. Performing the task correctly isimportant, and desirably is not undertaken simultaneously with flyingthe aircraft and listening to the radio. Even when an assistant isavailable to perform the calculations, the opportunity for human errorsuggests the desirability of an apparatus which simplifies the task andminimizes error. A need remains, therefore, for a system and apparatusfor receiving raw meteorological data and calculating therefromadditional derived meteorological and related information useable by apilot, without the pilot having to be distracted while operating theaircraft itself. Against this background, the present invention wasdeveloped.

SUMMARY OF THE INVENTION (DISCLOSURE OF THE INVENTION)

The invention relates to an apparatus for assisting pilots and others ineasily and rapidly obtaining accurate raw and calculated meteorologicaldata for use in making judgments in the course of flying an airplane,helicopter, or other aircraft. Broadly described, the invention is areceiver-calculator unit, useable in combination with a ground-basedweather station transmitter. The unit preferably is portable, so that itcan be removably placed in an aircraft, or be hand-held outside theaircraft, or be moved from aircraft to aircraft. Disposed within theunit housing are signal receiver components and electronic calculationcomponents of generally known construction. A central processing unit inthe unit permits the processing of data transmitted from theground-based station to calculate additional useful derivedmeteorological information for viewing upon a unit display.

The ground-based transmitter obtains raw meteorological data fromvarious measurement devices on the station, and also may be programmedto transmit certain site-specific physical data, such as runway length,runway altitude, and other information useful to a pilot's decisionmaking. The transmitter transmits signals conveying the raw dataconcerning meteorological conditions at the ground-based station, aswell as site-specific information, to a signal receiver disposed insidethe unit housing. Digitized raw meteorological data is then transferredelectrically from the receiver to the central processing unit, whichcalculates derived meteorological information at least in part from theraw meteorological data accepted from the signal receiver. The inventionalso includes some means for the operator to manually input into the CPUsite-specific physical data of interest. In the case of airstrips, thisphysical data usually and preferably includes information about therunway, most particularly the heading (directional layout with respectto north) of the runway, or runway altitude or runway length. Thesite-specific physical data, such as runway heading, is a variable thatalso may be manipulated within the CPU to generate derivedmeteorological information.

The invention preferably includes at least some digital memory forstoring both raw and input data as well as derived data. The memory isin communication with the CPU, so that data may be placed into andretrieved from memory by the CPU according to known digital calculationprocesses. Raw meteorological data from the receiver may be sentstraight through for viewing upon the display on the unit, and/or may besent to storage memory for later recall and processing. Likewise,physical data input from the data input may be stored for laterprocessing in the CPU.

A primary object of the present invention is to provide an economicalsystem and apparatus, useable at small, isolated, unstaffed, or privateairports, for readily providing pilots with very local meteorologicaldata and information.

A primary advantage of the present invention is that it can beeconomically manufactured.

Another advantage of the invention is that it frees a pilot flying anaircraft from having simultaneously to listen to audio weatherbroadcasts, if they are even available, and from having to fumble withcharts, slide rules, conventional arithmetic calculators, and pencilsand paper, in order to obtain weather data for use in flying theaircraft or making pre-flight decisions.

Accordingly, there is provided in accordance with the invention anapparatus useable in combination with a ground-based weather station,the station transmitting signals conveying raw data concerningmeteorological conditions at the station, the apparatus comprising asignal receiver for receiving the transmitted signals, a centralprocessing unit for calculating derived meteorological information atleast in part from the raw meteorological data accepted from the signalreceiver, and means for displaying the raw meteorological data and thederived meteorological information. Preferably, site-specific physicaldata also is conveyed from the ground-based station to the signalreceiver. Preferably, the signal receiver comprises a radio receiver.The raw meteorological data may comprise one or more members selectedfrom the group consisting of temperature, relative humidity, averagewind speed, average wind direction, wind gust speed, and wind gustdirection, while the derived meteorological information comprises atleast one member selected from the group consisting of density altitudeand dew point temperature. When the ground-based station is at anairport runway, there is provided some means for inputting into thecentral processing unit site-specific physical data regarding therunway, such as runway heading, altitude, and length. In alternativeembodiments, there maybe means for inputting data concerning aircraftperformance characteristics particular to the aircraft in use. When theground-based station is at a golf course, there is provided some meansfor inputting into the central processing unit physical data respectinga fairway, and the derived meteorological information further comprisescrosswind speed. At airports, the derived meteorological information maycomprise crosswind speed and/or headwind speed. The means for displayingdata comprises at least one member selected from the group consisting oflight-emitting diodes and liquid-crystal displays.

Other objects, advantages and novel features, and further scope ofapplicability of the present invention will be set forth in part in thedetailed description to follow, taken in conjunction with theaccompanying drawings, and in part will become apparent to those skilledin the art upon examination of the following, or may be learned bypractice of the invention. The objects and advantages of the inventionmay be realized and attained by means of the instrumentalities andcombinations particularly pointed out in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated into and form a partof the specification, illustrate several embodiments of the presentinvention and, together with the description, serve to explain theprinciples of the invention. The drawings are only for the purpose ofillustrating a preferred embodiment of the invention and are not to beconstrued as limiting the invention. In the drawings:

FIG. 1 is a perspective view of one embodiment of the portablereceiver-calculator unit according to the invention, held in a user'shand;

FIG. 2 is a front view of the embodiment shown in FIG. 1;

FIG. 3 is an elevation view of the ground-based weather station useablewith the present invention; and

FIG. 4 is a schematic diagram illustrating the interaction of variouselements of the apparatus of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS (BEST MODES FOR CARRYING OUTTHE INVENTION)

The invention has to do with a system and apparatus for supplyingmeteorological information in a readily usable form to persons,particularly small aircraft pilots. The invention may be adapted for usein other fields of endeavor, for example boating and golf, where weatherconditions, and the directional relationship between wind direction andlocal features (such as direction of sailboat travel or layout of a golfcourse fairway), are important factors. It is contemplated, however,that the invention finds utmost utility in the field of aviation.Operators of small private aircraft, especially non-commercial airplanes(commonly called “general aviation”), but also including helicopters andeven hot air balloons, may utilize the invention. The apparatus permitsthe pilot to more reliably and safely receive and utilize weatherinformation to perform flight maneuvers, most particularly take-offs andlandings, at small private airfields, heliports, and seaplane bases.

Attention is invited to FIG. 1, showing the receiver unit apparatus 10of the invention, shown being held in a user's hand. The apparatus 10preferably is sized to be readily portable (for example for transferfrom airplane to airplane), but may be larger than the scale depicted inthe figures. Alternatively, the apparatus 10 may be permanently mountedwithin an aircraft. The receiver unit 10 has a housing 12 composed ofplastic or other rigid, durable material suitable for containing andprotecting a signal receiver, preferably a radio receiver, and computerprocessing components. Housing 12 maybe provided with connectors (notshown) thereon, such as brackets, VELCRO® fastener strips, or the like,with which the unit 10 can be releasably and temporarily engaged withcomplementary mounts or fasteners upon the control panel or otherconvenient part of the aircraft cockpit. Ideally, the housing 12 can beopened to permit access to interior components for replacement andrepair.

The face of the housing 12 of the receiver and processor unit 10features a display 14 where useful data is displayed to the user. Datadisplay preferably is accomplished by conventional liquid-crystaldisplay (LCD) or light-emitting diode (LED) components, which permitdata collected and processed by the unit 10 to be viewed by the user.Also on the unit 10 are various buttons or switches for operation,including an a information refresh button 16, a runway heading settingbutton 18, a display light button 20, and an on-off switch 22, to bedescribed. The unit 10 has a conventional power source (not shown),which may be an internal battery and/or an input from the aircraft'selectrical system.

FIG. 3 shows a ground-based automated weather station 60 used with theinventive system. The weather station 60 is situated at the landingstrip or airport, and employs known technologies automatically to gatherfundamental meteorological information for periodic transmission to thereceiver-processor unit 10. The station 60 is fixed, as to a building orto a pole 70, to be in a stationary but elevated position upon theground. The station 60 is provided with a source of electrical power,such as a battery 62. Interconnection between the various components ofthe station 60 optionally may be provided by sheltering wiring andcables within the hollow pole 70. The battery 62 may be rechargeable byan electrically connected conventional solar energy collector panel 61,e.g. photovoltaic cells. Alternatively, the station 60 may be powered byconnection to the public utility grid via a transformer, etc.

The station 60 has a pressure and humidity module 64 containing abarometer and hygrometer. Real-time data regarding barometric pressureand relative humidity at the station 60 are obtained at the pressure andhumidity module 64. The barometric and hygrometric data is provided to aradio transmitter 66 for transmission to aircraft in the vicinity (e.g.within about two miles radius and under 2,000 feet above ground level).Transmitter 66 broadcasts raw weather data at a suitable approvedfrequency, for example between about 900 megahertz and about 2.3gigahertz. Transmitter 66 also may be pre-programmed to transmitsite-specific physical data about the runway (length, altitude, and thelike). Transmitter 66 may include modest digital signal processing andother elements, for example amplifiers, for pre-processing received dataprior to its broadcast from the transmitter 66. Similarly, transmitter66 preferably includes a timing circuit of known construction wherebytransmission of updated collected meteorological data occurs at periodicintervals, for example every ten seconds.

Other data gathering instruments in the station 60 include a thermometermodule 63 having one or more thermometers for measuring ambient airtemperature at the station 60. Preferably, thermometer module 63 has atleast one centigrade and one Fahrenheit thermometer, and can be eitherdigital or analog. Temperature data is sent to the transmitter 66 tothen be transmitted to the receiver unit 10. Mounted near the top of thestation 60 are a vane 67 and anemometer 68, for obtaining real-timemeasurements of wind direction and speed. Simple microprocessors at thestation 60, for example housed with the transmitter 66, process inputfrom the vane 67 and from the anemometer 68 to determine average windspeed and average wind direction in a generally conventional manneraccording to the following formulae:

For average wind speed: $\begin{matrix}{V_{AVG} = {{\sum\limits_{V_{1}}}^{V_{N}}{{V_{X}/N}\quad {for}\quad 2\quad {minutes}}}} & (1)\end{matrix}$

and for average wind direction: $\begin{matrix}{D_{AVG} = {{\sum\limits_{D_{1}}}^{D_{N}}{{D_{X}/N}\quad {for}\quad 2\quad {minutes}}}} & (2)\end{matrix}$

The average wind speed and direction are sent to the transmitter 66 fortransmission to the receiver in the unit 10. Also accompanying thetransmitter 66 preferably is a gust calculator (not shown). The gustcalculator uses known means and methods for determining the peak(maximum) wind speed over each one of serial, successive, prescribed(e.g. two-minute) intervals, and the wind direction at the instant ofeach interval's maximum gust. The peak gust speed and direction thereofis then transmitted by the transmitter 66. The maximum gust speed anddirection information is updated and broadcast at regular (e.g. twominute) intervals. Similarly, the dew point temperature at the station60 may be calculated by processors at the station according to formula(3) hereinafter for transmission to and display at the unit 10, or dewpoint may be calculated in the unit itself as described hereafter. Theoverall instrumentation, configuration, and function of the privateweather station 60 is within the known arts, but its integration intothe complete system of the invention is believed to be innovative.

The general construction and function of the invention is indicated inFIG. 4. The unit containing the receiver 70 and central processing unit71 is disposed within the aircraft. The transmitter 66 obtains rawmeteorological data from the various modules of the station 60. Rawmeteorological data includes, for example, temperature, relativehumidity, average wind speed, average wind direction, wind gust speed,and wind gust direction, as explained above. The transmitter 66transmits signals conveying raw data concerning meteorologicalconditions at the station 60 to a signal receiver 70, disposed insidethe housing 12, for receiving the transmitted signals. The transmitter66 preferably is a radio transmitter of comparatively modest wattage,and the receiver 70 preferably is a radio receiver of knownconstruction.

Digitized (as by a standard analog-digital converter) raw meteorologicaldata is then transferred electrically from the receiver 70 to a centralprocessing unit (CPU) 71 which also is disposed within the housing 12 ofthe unit 10. The CPU 71 is a digital computer for calculating derivedmeteorological information at least in part from the raw meteorologicaldata accepted from the signal receiver 70. The CPU processes the rawdata using algorithms, to be further explained, to determine derivedmeteorological information. Derived meteorological information isinformation concerning weather conditions that are not directly measuredat the station 60, but rather is derived from mathematical processing ofraw input data. Derived meteorological information includes, forexample, density altitude, and dew point temperature. The invention alsoincludes some means for the operator to input into the CPU 71 physicaldata respecting the topography of interest. In the case of airstrips,this physical data usually and preferably includes information about therunway, most particularly the heading (directional layout with respectto north) of the runway. Alternatively, physical information to be inputin other fields of use includes, for example, the heading of a goldcourse fairway. In the preferred embodiment, the physical data about therunway or fairway heading is input using the runway heading settingbutton 18, which is operatively electronically connected with the CPU71. The physical data, such as runway heading, is a variable that alsomay be manipulated within the CPU 71 to generate derived meteorologicalinformation. For example, the runway heading value can be mathematicallyprocessed, together with the average wind speed and direction receivedfrom the receiver 70, in the CPU to calculate the crosswind and headwindvalues at the runway. Thus, derived meteorological information alsooptionally includes information based on a combination of rawmeteorological data and data input by the operator regarding physical ortopographical character of a runway or golf course fairway.

As shown in FIG. 4, the invention preferably includes at least somedigital memory 72 for storing both raw and input data as well as deriveddata. The memory 72 is in communication with the CPU 71, so that datamay be placed into and retrieved from memory by the CPU according toknown digital calculation processes. Raw meteorological data from thereceiver 70 may be sent straight through for viewing upon the display 14on the unit 10, and/or may be sent to storage memory 72 for later recalland processing. Likewise, physical data input from the data input 18 maybe stored for later processing in the CPU 71. The operator sets thephysical data input values by referring to values that are “dialed” uponthe display 14. Derived meteorological information rendered in the CPU71 are sent from the CPU for viewing by the user upon the display 14.The display 14 on the unit housing 12 preferably is an arrangement of aplurality of liquid-crystal or light-emitting diode display componentsin electronic communication with the CPU 71.

In sum, the unit 10 is a combined signal receiver and calculator.Disposed within housing 12 are signal receiver components (preferably aradio receiver 70) and electronic calculation components, i.e. the CPU71, of generally known construction. The CPU, which accesses thecomparatively modest memory 72 but preferably features a high clockspeed, is within the unit housing 12. The CPU 71 permits the processingof data transmitted from the station 60 to calculate additional usefulderived meteorological information for viewing upon the display 14.

Attention is returned to FIGS. 1 and 2. The on-off switch 22 on unit 10preferably is an ordinary toggle switch for actuating and deactivatingthe unit 10, for example by connecting or disconnecting the unit's powersupply. A refresh button 16 clears from the unit's immediate memory 72any data previously received from the transmitter 66 at the privatestation 60. The unit's memory 72, once purged by the depression of therefresh button 16, is freed to receive and digitally store updated rawmeteorological data more recently transmitted from the transmitter 66and received by the receiver 70, which in turn permits the internal CPU71 to run another iteration of calculations to generate derivedmeteorological information. The unit 10 in more sophisticatedembodiments may be provided with a plurality of memories, whereby ageddata may be retained in secondary non-immediate storage while mostrecently received data from the station 60 is processed and displayedfor use. A display light button 20 activates a small display light topermit viewing of the display 14 in dark conditions, particularly forembodiments using an LCD type of display screen. The runway headingsetting button 18 is a switch of known construction whereby the user isable to input the heading (in degrees) of the runway of interest. Bydepressing the “plus” side of the button 18, the runway heading figureindicated in the runway heading section 52 of the display 14 isincrementally increased; likewise, depressing the “minus” side of thetoggle, the runway heading value is decreased. The runway button 18 thuspermits the user to select an appropriate value for the runway heading,between zero and 360 degrees, to be processed in the CPU 71. Forexample, a runway heading of nine degrees has been entered for displayin FIG. 1.

The unit display 14 has various sections where particular information isdisplayed to the user. The display sections correspond to indicatinglabels on adjacent portions of the housing 12. Preferably, each displaysection has a separate LED or LCD component, so that each displaysection functions individually in conjunction with the CPU 71. By way ofparticular exemplary description, combined reference to FIGS. 1 and 2illustrates that in one embodiment, the dew point temperature displaysection 54 (displaying 97 degrees in FIG. 1) is adjacent to a “dew pointtemp” label on the adjoining housing. Alternatively, data-identifyingindica may be supplied directly within the display 14 by electronic orother graphical means.

In the preferred embodiment, the display 14 features a plurality ofdisplay sections whereon various items of data are displayed forviewing. As seen in FIG. 2, a wind speed display section 34 is wherewind speed (typically in knots), at the anemometer 68 (FIG. 3), isshown. For example, 21 knots is displayed in the wind speed displaysection 34 of FIG. 1. Wind direction in degrees at the vane 67 isdisplayed in wind direction display section 36, the direction of 300degrees shown by example in FIG. 1. Similarly, barometric pressure atthe station 60 is displayed in the pressure display section 30,temperature at the station 60 is displayed in the temperature displaysection 38, the wind gust speed (e.g. maximum for most recent two-minuteinterval) and direction are viewed in the gust display section 40, andrelative humidity at the station 60 is viewed within the humiditydisplay section 44. The foregoing values are raw meteorological datareceived by signal from the transmitter 66 and displayed directly forviewing by the user. A low battery indicator 56 may be provided to alertthe user to an expiring internal battery.

Also viewable on the display 14 is derived meteorological informationgenerated by the unit 10 by processing the raw meteorological data sentfrom the station 60. The direct cross wind speed (in knots, for example)at the airport runway, or more specifically, at the station 60 very nearthe runway, is displayed in cross wind display section 46. “Cross wind”is the component of wind speed blowing perpendicular to the runway.Similarly, the head wind at the runway appears in the headwind displaysection 50. Head wind is that fractional component of the total windspeed that blow parallel to the runway (with aircraft typically landing“into” the wind). An advantage of the invention is that it provides thepilot with crosswind and head wind information rapidly and effortlessly,despite the fact that the actual direction of the wind normally is atsome non-orthogonal direction with respect to the runway. Densityaltitude is shown in the density altitude display section 48. “Densityaltitude” has the meaning assigned in the field of aviation, and is ameasurement of air density in terms of altitude, but also as affected bytemperature, humidity, and barometric pressure. For example, air densityat an air strip located on a 7,000-foot plateau differs from air densityat sea level, and density altitude at either location can vary due tochanges in local air temperature, pressure, and humidity. Information isseparately presented in each of the distinct display sections 30-54 byLCD or LED display components in signal communication with the internalCPU 71 and storage memory 72 components of the unit 10.

The CPU 71 within the housing 12 utilizes digital programming todetermine several items of is derived information from the raw datatransmitted from the station 60. Dew point, for example, is determinedfrom the relative humidity and temperature data received by the receiver70 from the station transmitter 66. Temperature data and relativehumidity information is transmitted to the unit 10 from the station. Therelative humidity is directly displayed in the relative humidity displaysection 44, and the temperature likewise is displayed immediately in thetemperature display section 38. The CPU 71 accepts the temperature andrelative humidity data from the receiver 70, and determines the localdew point. First, the dew point temperature in degrees centigrade iscalculated from the following algorithm $\begin{matrix}{{{{DP}\left( {{{^\circ}C}.} \right)} = {238.3/\left( {{1/N} - 1} \right)}}{{{Where}\text{:}\quad N} = {\left\lbrack {{\ln \left( \frac{{RH}\%}{100} \right)} \times \frac{1}{17.2694}} \right\rbrack + \left\lbrack \frac{T\left( {{^\circ}\quad {C.}} \right)}{{T\left( {{^\circ}\quad {C.}} \right)} + 238.3} \right\rbrack}}} & (3)\end{matrix}$

And where RH % is the relative humidity measured by the pressure andhumidity module 64 and transmitted by the transmitter 66, and T is thetemperature in degrees centigrade measured at the thermometer module 63and transmitted. In is the natural log. The dew point in degreesFahrenheit is then determined from the metric dew point determined fromEquation (3), according the formula

DP(F°)={fraction (9/5)}DP(°c.)+32  (4)

The dew point in degrees Fahrenheit is then sent to the dew pointdisplay section 54 where it is available for viewing by the user. Dewpoint temperature can be used by pilots to ascertain valuableinformation about altitude (both of the aircraft and of clouds) due toknown temperature lapse rates and pressure decreases attributable toincreases in altitude.

The CPU 71 also accepts raw atmospheric pressure and temperature datafrom the receiver 70 to determine the density altitude value for use bythe pilot. Raw barometric pressure data is displayed directly in thepressure display section 30 for viewing. Density altitude (to 12,000feet) is determined in the CPU 71 from the following algorithm:

h=(11,346−148,300ρ)/(0.37921−ρ)  (5)

Where: ρ=(P)(M)/(R)(T)

=P(29)/(21.85)(T_(F)+460)

Where: ρ=Atm pressure in inches Hg

T_(F)=Temperature in ° F.

The calculated density altitude value is then sent to the densityaltitude display section 48 for viewing. Density altitude is used todetermine aircraft landing and take-off characteristics as a function ofaircraft weight. The CPU 71 may be programmed with known formula fordetermining these aircraft-specific characteristics.

Information about crosswind and headwind is of tremendous value to thepilot. The invention provides crosswind and headwind data to the pilotby permitting the pilot to enter into the CPU 71 specific topographicinformation about the airport, specifically the directional heading ofthe runway to be used. Prior to takeoff or landing, the pilot selects oris instructed which of more than one available runway will be used; morecommonly, private airstrips have a single runway. With the runwayidentified, the pilot employs the runway heading setting button 18 toinput the heading of the runway into the CPU 71. The runway heading ispreviously known from maps, compass, or information from an airportfixed base operator, for example. The user repeatedly depresses (orotherwise actuates) the appropriate side of the dual-contact runwayheading setting button 18 to increase or decrease the value displayed inthe runway heading display section 52 until the proper correspondingrunway heading value is indicated. The runway position information thenis available to the CPU 71. When the correct runway heading appears inthe runway heading display section 52, the runway heading data may besent to the CPU 71 and/or memory 72 by, for example, depressing theentire button 18 (as distinguished from the dual sided button action).

With the runway heading entered by the user into the CPU 71, the unit 10is able to determine vital headwind and crosswind information from thewind speed and direction data received from the transmitter 66 (andperhaps previously placed in memory 72). Raw data about wind speed(knots) and direction (heading degrees) is available from the receiver70 or memory 72 for display directly upon the wind speed display section34 and wind direction display section 36, respectively. This wind speedand direction information is manipulated, in combination with the inputrunway heading value, and converted by the CPU into useable derivedheadwind and crosswind data according to the following algorithms:

For crosswind speed:

Crosswind speed: (Knots)V_(cw)  (6)

V_(cw)=V_(w)[sin (D_(rw)−D_(w))]

Where: (+) If Left Wind, (−) If Right Wind

V_(cw)=Wind Speed, (Knots), D_(rw)=Runway Heading

D_(w)=Wind Heading

and for headwind speed:

Headwind Seed: (Knots)V_(HW)  (7)

V_(HW)=V_(w)[cos (D_(rw)−D_(w))]

Where: (+) Headwind, (−) Tailwind

V_(w)=Wind Speed, (Knots), D_(rw)−Runway Heading

D_(w)=Wind Heading

An exemplary use of the invention may now be summarized. The airport, orother alternative facility of interest such as a marina or golf course,is provided with the ground-based weather station 60 depicted in FIG. 3.The transmitter 66 periodically transmits radio signals conveying rawdata concerning meteorological conditions at the station 60. The user,such as an aircraft pilot, approaches the airstrip in an aircraft whosecockpit is equipped with the unit 10 depicted in FIGS. 1 and 2. Thepilot turns the unit on by actuating the on-off switch 22. Signalsconveying raw meteorological data are received from the transmitter 66by the receiver 70 for transfer to the CPU 71 and/or the unit memory 72.In the event of cockpit darkness, the pilot may actuate the displaylight button 20 if required.

The raw meteorological data is displayed in the display 14. Currentaverage winds speed is viewed at the wind speed display section 34,while current average wind direction is viewed in the wind directiondisplay section 36. (Barometric pressure is used by a pilot to set theaircraft barometric altimeter to local barometric pressure.) Thebarometric pressure at the station 60 appears in the pressure displaysection 30. The ambient temperature is displayed in the temperaturedisplay section 38. Relative humidity is available for viewing in thehumidity display section 44. The pilot also may view the gust speed anddirection, as transmitted from the station 60, in the gust displaysection 40. The pilot may, if desired and possible, make certainaircraft operation decisions and plans based upon the foregoing rawmeteorological data. Continuing, the pilot inputs the runway headingvalue using the runway heading setting button 18 so that the runwayheading value appears in the runway display section 52. The entirerunway heading setting button is depressed to send the runway headingdata to the CPU 71. The CPU 71 engages microprocessors which retrievethe appropriate values of the respective raw meteorological data, andapply the algorithms set forth at Equations 3-7 herein, to calculatederived meteorological information, such as cross wind speed, headwindspeed, density altitude, and dew point temperature. The derivedmeteorological information is displayed in respective ones of thedisplay sections 46, 50, 48, and 54 where they may be viewed by thepilot operator. Notably, the pilot does not have to manipulate any sliderule, refer to any graphs, or operate a standard electronic calculator.The derived meteorological information is automatically generated anddisplayed for use in flying the airplane. In the event the pilot doesnot make immediate use of the received and calculated data, for example,in the event the airstrip is circled for a period of time, the pilot canupdate all the data in preparation for landing. The runway headingsetting button is not used again, since the runway position isunchanged. The pilot simply pushes the refresh button 16, at which timethe receiver 70 receives signals conveying updated raw meteorologicaldata, and the CPU 71 reruns the algorithms to generate updated derivedmeteorological information. The updated information may then be used toproperly configure the aircraft for landing.

In sophisticated embodiments of the invention, the CPU in the unit 10maybe pre-programmed with data (aircraft empty weight, take-offdistances at standard conditions, and the like) customized to theparticular model of aircraft in which it is to be used. Also, the unit10 may be provided with an input whereby the pilot inputs not only therunway heading, but also runway length. Also, an input button, similarto runway heading input button 18, may be provided whereby the pilot mayinput the weight of passengers and cargo. In these advanced versions ofthe invention therefore, a safety program is provided in the CPU sothat, in the event that the current meteorological conditions at therunway (as received and calculated by the unit 10) preclude a safelanding or take-off by the type/weight of aircraft in use, a visualand/or audible alarm is activated on the unit 10.

For example, the CPU 71 may be custom-programmed to contain the take-offcharacteristics (such as required runway length) of the specificaircraft in use, when supplied with real-time data about densityaltitude and passenger/cargo weight. Such characteristic algorithms areknown in the art, and their installation into a CPU is within theordinary skill of computer programmers. Thus, the operator of theinvention may take the apparatus of the invention prior to take-off, anduse it to ascertain the safety of a proposed take off. The unit 10receives transmitted raw meteorological data (e.g., temperature andpressure) from the transmitter 66, and determines, stores, and displaysthe calculated density altitude. The unit 10 also receives and storessite-specific physical data, such as runway heading and length,broadcast by the transmitter 66, or the pilot alternatively inputs suchsite-specific data into the CPU 71 using buttons similar to the runwayheading setting button 18. The unit 10 derives cross and head wind dataas previously described. The pilot inputs the weight of cargo andpassengers into the CPU as additions to total aircraft weight. The CPU71 then enters the density altitude value, headwind value, runwaylength, aircraft weight, and other pertinent variables into thepreprogrammed aircraft performance algorithms, and determines if a safetake-off may be performed under the particular conditions. If safety isquestionable, an audible and/or visible alarm is activated.

In alternative embodiments, the invention is used at golf courses. Thestation 60 is installed at a central location at the course. A unit 10is carried by a golfer, who can input the physical data (e.g. heading)of a fairway, and then operate the unit 10 to provide wind speed anddirections, including cross winds and headwinds, helpful in evaluatingthe swing necessary to compensate for the ambient conditions effects onthe flight of the ball.

Although the invention has been described in detail with particularreference to these preferred embodiments, other embodiments can achievethe same results. Variations and modifications of the present inventionwill be obvious to those skilled in the art and it is intended to coverin the appended claims all such modifications and equivalents. Theentire disclosures of all references, applications, patents, andpublications cited above are hereby incorporated by reference.

What is claimed is:
 1. An apparatus useable in combination with aground-based weather station, wherein the ground-based station is at anairport runway, the station transmitting signals conveying raw dataconcerning meteorological conditions at the station, said apparatuscomprising: a signal receiver for receiving the transmitted signals; acentral processing unit for calculating derived meteorologicalinformation at least in part from the raw meteorological data acceptedfrom said signal receiver; means for inputting into said centralprocessing unit physical data respecting the runway, said physical dataselected from the group of site-specific data consisting of runwaylength, runway altitude, and runway heading; and means for displayingthe raw meteorological data and said derived meteorological information.2. An apparatus according to claim 1 wherein said signal receivercomprises a radio receiver.
 3. An apparatus according to claim 2 whereinthe raw meteorological data comprises at least one member selected fromthe group consisting of temperature, relative humidity, average windspeed, average wind direction, wind gust speed, and wind gust direction.4. An apparatus according to claim 3 wherein said derived meteorologicalinformation comprises at least one member selected from the groupconsisting of density altitude and dew point temperature.
 5. Anapparatus useable in combination with a ground-based weather station,wherein the ground-based station is at a golf course, the stationtransmitting signals conveying raw data concerning meteorologicalconditions at the station, said apparatus comprising: a signal receiverfor receiving the transmitted signals; a central processing unit forcalculating derived meteorological information at least in part from theraw meteorological data accepted from said signal receiver; means forinputting into said central processing unit physical data respecting agolf course fairway, said physical data comprising fairway heading; andmeans for displaying the raw meteorological data and said derivedmeteorological information, wherein said derived meteorologicalinformation compress crosswind speed.
 6. An apparatus according to claim1 wherein said derived meteorological information further comprises atleast one member selected from the group consisting of crosswind speedand headwind speed.
 7. An apparatus according to claim 2 wherein saidmeans for displaying comprises at least one member selected from thegroup consisting of light-emitting diodes and liquid-crystal displays.8. An apparatus useable in combination with a ground-based weatherstation at an airport runway, the station transmitting signals conveyingraw data concerning meteorological conditions at the station, saidapparatus comprising: a signal receiver for receiving the transmittedsignals conveying raw meteorological data; means for inputting into acentral processing unit physical data respecting the runway, whereinsaid central processing unit calculates derived meteorologicalinformation from the raw meteorological data accepted from said signalreceiver and from said physical data respecting the runway; means fordisplaying the raw meteorological data and said derived meteorologicalinformation.
 9. An apparatus according to claim 8 wherein said signalreceiver comprises a radio receiver.
 10. An apparatus according to claim8 wherein the raw meteorological data comprises at least one memberselected from the group consisting of temperature, relative humidity,average wind speed, average wind direction, wind gust speed, and windgust direction.
 11. An apparatus according to claim 8 wherein saidderived meteorological information comprises at least one memberselected from the group consisting of density altitude and dew pointtemperature.
 12. An apparatus according to claim 8 wherein said derivedmeteorological information further comprises at least one memberselected from the group consisting of crosswind speed and headwindspeed.
 13. An apparatus according to claim 8 wherein said means fordisplaying comprises at least one member selected from the groupconsisting of light-emitting diodes and liquid-crystal displays.
 14. Anapparatus according to claim 8 wherein said means for inputting into acentral processing unit comprises a data input button.
 15. An apparatusaccording to claim 8 wherein said means for inputting into a centralprocessing unit comprises said signal receiver for receiving transmittedsignals conveying said physical data.
 16. An apparatus useable incombination with a ground-based weather station at a site, the stationtransmitting signals conveying raw data concerning meteorologicalconditions at the station, said apparatus comprising: a signal receiverfor receiving the transmitted signals; a central processing unit forcalculating derived meteorological information at least in part from theraw meteorological data accepted from said signal receiver; means forinputting into the central processing unit site-specific physical datarespecting the site; means for displaying said site-specific physicaldata, said raw meteorological data, and said derived meteorologicalinformation.
 17. An apparatus according to claim 16 wherein said centralprocessing unit calculates derived meteorological information from theraw meteorological data accepted from said signal receiver and from saidsite-specific physical data.
 18. An apparatus according to claim 17wherein said site is an airport runway and wherein said apparatus isdisposable within a selected aircraft, and wherein said centralprocessing unit is programmed with data regarding the selected aircraftand regarding safe take-off or landing meteorological conditions for theselected aircraft; said apparatus further comprising: means forinputting the weight of passengers and cargo to be carried in theselected aircraft; and an alarm; wherein when said derivedmeteorological conditions at the runway preclude a safe landing ortake-off by the selected aircraft, said alarm is activated.
 19. Anapparatus according to 16 wherein said site is a golf course.
 20. Amethod for supplying meteorological information in a form which isreadily usable to a person, comprising: obtaining raw data concerning atleast one meteorological condition at a first location; transmittingsaid raw data to a remote device; receiving said transmitted raw data insaid remote device; calculating derived meteorological information atleast in part from said transmitted raw data; and selectivelydisplaying, on a display associated with said remote device, dataselected from the group consisting of said raw data, a portion of saidraw data, said derived meteorological information, a portion of saidderived meteorological information, a combination of said raw data andsaid derived meteorological information, and a combination of a portionof said raw data and a portion of said derived meteorological data;wherein said calculating of derived meteorological information isperformed in a central processing unit disposed in said remote device,and further comprising: inputting, into said central processing unit,site-specific physical data related to said first location.
 21. A methodas recited in claim 20, wherein the inputting of site-specific physicaldata into said central processing unit comprises receiving said physicaldata into said remote device from a remote transmission.
 22. A method asrecited in claim 20, wherein the inputting of site-specific physicaldata into said central processing unit comprises entry of data via adata input interface on said remote device.
 23. A method for supplyingmeteorological information in a form which is readily understandable toa person, comprising: storing physical data related to an airportrunway, in a processor in a remote device; obtaining raw data concerningat least one meteorological condition at a location near said airportrunway; transmitting said raw data to said remote device; receiving saidtransmitted raw data in said remote device deriving, using said storedphysical data and said raw meteorological data, meteorologicalinformation; and displaying, on a display associated with said remotedevice, at least a portion of the derived meteorological information.24. A method as recited in claim 23, wherein said processor comprises acentral processing unit and an associated memory, and wherein saidderiving of meteorological information is performed in said centralprocessing unit.
 25. A method as recited in claim 23 wherein saidphysical data stored in said processor is received into said remotedevice from a remote transmission.
 26. A method as recited in claim 23,wherein said physical data stored in said processor is received intosaid remote device via a data input interface on said remote device. 27.A method as recited in claim 23, further comprising displaying, on saiddisplay associated with said remote device, at least a portion of saidraw meteorological data.
 28. A method as recited in claim 23, furthercomprising obtaining raw data concerning at least two meteorologicalconditions at said location near said airport runway.